Took 14 days to fix my smoker's temp swings, it was a $4 gasket
My offset ran 40 degrees hot on the left side for weeks. I checked the door seal, the intake damper, even the stack height. Turned out the firebox door gasket was so worn it was sucking air like a vacuum. Replaced it with a new rope gasket kit from the hardware store, cost me 4 bucks and 20 minutes. Now it holds 250 within 5 degrees, has anyone else had a tiny part mess up their whole cook like that?